One particularly advantageous thermocouple design is the Right Angle Thermocouple, one embodiment of which is set forth in U.S. Pat. No. 3,283,580. This design features a thermal junction disposed at right angles to the longitudinal axis of the thermowell base structure in which the thermocouple is mounted, and generally supported by an extending insulating rod upon which the thermocouple junction sensing tip rests. The dissimilar metals in the vicinity of the junction are flattened ribbon-like strips. These are held parallel to the plane of the heat source or surface being monitored so that both the thermal junction and the ribbons are heated simultaneously to reduce conduction errors. The ribbon elements allow fast times to equilibrium temperature with a maximum surface contact area offered to the heat source. Thus response times of a few milliseconds is achieved.
However, there are several disadvantages of prior art right angle thermocouple embodiments. The thin ribbon structure is so fragile that damage to the junction is often encountered in contacting the object to be monitored. Also errors occur in temperature readings because of variations in contact pressure of the sensing tip from time to time. In storage or transit, the junction is easily damaged if it brushes against some other object.
Other problems and disadvantages are encountered with the prior art right angle thermocouple structures. Thus, the supports or mounting assembly for the ribbon junction elements may serve as a heat sink or temperature modifier that contacts the heat source or surface being monitored and thus introduce errors into the temperature readings.
It is therefore a primary objective of the present invention to improve the state of the art of right angle thermocouples. A further objective is to resolve the aforementioned problems and disadvantages of the prior art thermocouples. Other objects, features and advantages of the invention will be found throughout the following description, drawing and claims.